1.5 Better Together Version. Creative Mode, in Multiplay, multiple devices, my purchased Realm, using a purchased World from within Minecraft, Minecraft Store:

• Lenovo Thinkpad
• Surface Pro 4
• Xbox One
• Two different iPads
• iPhone 7

Multiplay and individual play, in my purchased Realms, is intended for extended family grandchildren, across United States and Europe! Occasionally, several are all in a single location.

I tried to attach .png pics, and .mp4 videos, but got a message about missing token.

Problem: Initially, Castles and Dragons worked in my purchased Realm, across the above devices, and across extended family grandchildren, in various United States and Europe locations. Then the 1.5.0 update happened! See attached files! The Resources and Behaviors :

• no longer Work properly. If the Resources and Behaviors do upload, the props behave as mobs gone wild, in total chaos!
• do not upload to the Realm! If the Resources and Behaviors do not upload, the props revert to base-Minecraft inventory mobs that result from base Minecraft Mob Eggs

Noxcrew has responded that

• the fix is up to Mojang
• their Worlds are tested for multiplay on Xbox live system, but NOT TESTED on REALMS! And NOT DESIGNED FOR REALMS!

Strong Recommendations:

• A statement needs to be added to EACH World (map or add-on), Mash-up, etc. in the Minecraft to SPECIFY what will and will NOT work in Realms!
• Mojang needs to fix the incompatibility so that the marketed Worlds, Mash-ups, etc, within Minecraft at the Minecraft Store do WORK properly in purchased Realms
• The elitist attitude among bug fixers needs to be adjusted to account for interrelated issues and  adequate communication and responses to bug reporters.